Women carrying deleterious BRCA mutations are expected to notify their relatives about the family's inherited cancer susceptibility. This is important because relatives have a 50% chance of harboring the same cancer- causing genes, and may themselves be at risk for breast and other cancers. Patients sometimes collaborate with a genetic counselor to follow this advice?disclosing their BRCA+ status to parents, adult siblings, and additional members of their kindred. Evidence suggests women with children also want to inform their daughters and sons about maternal BRCA+ genetic test results, but carrier mothers are often psychologically distressed after testing and have difficulty navigating the social and medical implications for their adolescent and young adult (AYA) offspring. It is common for these mothers to experience uncertainty over early notification of BRCA+ to AYAs, manage their own thoughts/feelings about familial cancer, and maintain open the lines of communication with relatives without `keeping secrets' from their own children. Although genetic counseling assists with aspects of this decisional and psychosocial burden, there are no evidence-based resources specifically devoted to ameliorating mothers' anxiety/depression, worry, and self-blame and traverse complex questions surrounding BRCA+ status notification to their AYAs. In response to this gap, we developed and successfully piloted a new, fully manualized psychosocial support and family communication decision making protocol for BRCA+ mothers with AYA children. Our intervention is theoretically-grounded, and deeply attends to self-management needs, hereditary cancer stresses, and age-appropriate AYA concerns. Following standard genetic counseling, it adds 3 sessions of brief telephone counseling delivered by well- trained peers (parent coaches) who are also BRCA+ mothers themselves. Coaching covers: a) maternal socioemotional support, b) communication decision making training, and c) coping skill-building. We will rigorously test for efficacy in a 2-arm RCT to determine improvements in maternal psychosocial functioning and parent-AYA child communication outcomes after standard genetic counseling. BRCA+ mothers with AYA daughters and sons will be recruited from cancer genetic testing centers in the greater DC and Hackensack, NJ areas, randomized to an intervention or usual care control condition, and monitored for up to 6 months post- treatment. Our results should provide evidence for favorably impacting this population's genetic counseling outcomes, with a disseminable intervention poised for adoption. Peer support may be conventional within the breast cancer community at-large, but it remains an unproven treatment ally in genetically informed oncology care. The proliferation of genetic tests, and the modest genetic counseling workforce, necessitate new healthcare delivery models that leverage these and other accessible resources. Targeted peer coaching with an empirical decision support aide could prove to be a viable extension of genetic counseling efforts with BRCA+ mothers, and a complementary approach to hereditary cancer prevention and control in public health settings.